8. A bespoke stream

For almost 35 years, the streams feeding into the Llyn Brianne reservoir, in upland Wales, have provided a living laboratory enabling detailed study of river ecosystems and their functions, and providing an unrivalled longitudinal record of the environmental and biological changes in the rivers of upland Wales. The data researchers have accumulated is so unique, that it is now to be recognised as a Long Term Ecological Research site (www.llyn-brianne.org).

In 2013 we installed these artificial experimental cascades to perform experiments in real life conditions. They are the first cascading channels to be built in an upland landscape. These channels mimic real rivers but allow us to control any variation. For the first time, we can now start to quantify the role that river biodiversity such as biofilms and invertebrates play in controlling water chemistry. And of course we can do much more, experimenting with changing climate or changing stressors.